Brake lining



Jan. 22, 1929. Y 1,700,03'?

R. J. EVANS BRAKE LINING Filed Jan. 20. 1928 2 Sheets-Sheet l im n.1"

Jan. 22, 1929.

R. J. EVANS BRAKE LINING Filed Jan. 20. 1928 2 Sheets-Sheet 2 l ZmventorE. J. Eva/mf ll/:em f a CttornegS Patented Jan. 22, 1929.

c AUNITED 'STATES PATENT OFFICE. l

RICHARD J. EVANS, F HUNTINGTON, INDIANA, ASSIGNOR TO ASIBESTOS MANUFAC-TUBING COMPANY, OF HUNTINGTON, INDIANA, A CORPORATION OF INDIANA.

BRAKE LIN-ING.

I Application filed January 20, 1928.A Serial No. 248,206.

My invention relates to an improved construction of brake lining for'thei friction brakes of automobiles, trucks, or the like vehicles, orfor use in braking rotary drums l or shafts of any kind where it isdesired to secure quick and efficient adjustment of the brake, and inwhich the brake lining doesl not tend to stick to the drum when'released and in which the wear takes place uniformly, l0 as theengaging surface' of the brake lining wears. tended to provide a brakelining having a high co-efficiency of friction and great durabilityunder intense wear, uniformity of friction resistance substantiallyunaffected by moisture and temperature conditions, and which does notstick when the brake lever is released.

My invention will be more clearly understood after reference to theaccompanying drawings in whichlike parts are indicated by similarreference symbols throughout the several views, and in which Figure 1shows a strand of asbestos fiber twisted comparatively tightly, butwithout the addition of any other material.

Figure 2 shows two strands of asbestos of Figure 1 having combinedtherewith strands of fine flexible wire.

Figure 3 shows a woven fabric made of the strands of Figure 2, which arepermeated before weaving with a fireproof liquid such as silicate ofsoda, the warp threads and the woof threads being of equal'strength andcrossing each other at equal intervals so as to give equal strength tothe material in either transverse or longitudinal direction.

Figure 4 shows the fabric of Figure 3 after it has been thoroughlydried, and after it has been coated on one side with a mineral frictioncompound composed of rubber and other material, as will be hereinafterdescribed.

Figure 5 shows a cross section of Figure 3 along the line 5-5 of saidfigure.

Figure 6 shows a cross section of Figure 4 along the line 6 6 andlooking in the direction of the arrows. i

Figure 7 shows a strip of brake band corn- In other words, my inventionis in- Figure 9 shows a roll of the brake band lining ready forshipment, which should be cutdinto strips of the desired length when useIn the manufacture of my improved brake lining, first I-twist the fibersof asbestos as secured from the rock into special hard multiple'yarns a,as shown in Figure 1.v A

Then I twist up with one or more of these asbestos yarns one or morestrands of fine wire 7;, for example, .008 brass wires, the

product being a cordof twisted'yarn and wire,

as shown in Figure 2. These cords are then treated with the permeatingfire-proof liquid solution containing silicate of soda (water glass),and after such treatment and partial drying, these yarns are woven intoan open mesh or fabric A, as shown in Figurev3. The weaving is of theordinary basket weave, and the woof threads are'preferably of the samestrength and distance apart as are the warp threads, so that the fabricis-of substantially the same strength transversely and longitudinally.

After the fabric has been so formed, it is treated and thoroughl driedso as to harden the fireproof liquid so ution, causing the silicate tocement the asbestos fibers together, thus producing a hardened wovenfire-proof fabric.. This fabric, shown at A in Figure 3, is thentreatedon one side only as at B in Figure 4 with a mineral friction com ound,which consists of rubber, litharge, an other ingredients, such asbarytes, asbestine, sulphur, in a warm or plastic state, and the strip,so treated on one side, issubjected to high pressure, so as to forcethis plastic material from the back to the front of the fabric fillinginterstices between the cords, but leaving the wear surface of the stripnot covered over with this plastic material. l A series of strips, suchas shown in Fi re 6, are then folded over or superpose as shown inFigures 7 and 8, where I show three of such strips, but two or more maybe used if desired. In superposing these strips, the coated side B ofeach strip is adjacent tothe uncoated side A of the adjacent strip, as

lshown most clearly in Figure 8. This is important because in the formerpractice of making brake bands it has been generally customary to coatboth sides of each strip before these strips are superposed with theresult that there is a doubling of the coatingv at the adjoiningsurfaces of the adjacent strips; Whereas by coating each strip ononeside only, a substantially uniform coating of rubber material willpermeate the entire mass.

As the brake band Wears down, t-liere will be very little variation inthe nature of the friction surface exposed to the drum.

After the strips are superposed, as just mentioned, to form fthe liningfor a brake band, they are subjected to higlipressure and sufficientheat to cure or vulcanize the rubber to the desired extent, so that thestrips will not only adhere to form a substantially homogeneous band,but the material contained in the rubber Will be properly held therein.i

After being prepared asabove described, the lining may be treated with asolution of fire and Water proofing material composed of suitableoxidizing oils, China Wood, or rosin oils, or other similar liquids,`which Will be converted into carbon under heat, and,

after being so treated, the lining is again' heated or baked at a hightemperature for a suflicient period, five hours, more or less, for

a final treatment.

After such treatment, the product is an aged or cured brake lining, andis better able to withstand Wear and heat.

A strip .of the finished brake lining band is shown in Figure 7 andFigure V8 shows an enlarged section of the same, While Figure 9 shows along strip of the brake lining made up into a roll ready to be shippedto the consumer, suitable lengths of the brake lining being cut from theroll as desired.

In use, the coated part B of the strips of brakelining should bepreferablyfurthest from the engaging surface of the brake drum. By thisconstruction, there will be little or no tendency of the rubber'toflow'and stick on the braking surface of the lining, as occurs Where therubber shim is applied to both sur# faces of the strips before beingassembled into the completed lining. If there is an excessive amount ofrubber on this side, there will be a tendency for this to fuse and stickto the drum, preventing the brake lining from becoming disengagedpromptly when the brake lever is released. 4

When the brake liningis first applied this shim coat of rubber causesthe brake to grab When the same becomes 'heated and to give a very lowco-efticient of friction When cold. The presence of this layerofr'rubber has been found so undesirable that many manufacturers havefound it necessary to grind or burnish the lining to remove the outercoating of rubber. This grinding results in the removal of some of thedesirable thickness ofthe lining. -I'have discovered that by apk' plyingthe. friction compound to one 'side only, which isdone by heavycalenders and forcing the friction'material into and just through theopen mesh of the cloth, it results in the construction of a brake liningwhich" runsuniform in construction all the Way.-

through the lining. It results in the production of a lining Whosesurface never changes materially no mat-ter how much it isl Worn.

lHaving thus described my invention, what I claim and desire to secureby Letters Pat-V ent of the United States is including fine `Wirestrands,treating these cords `With a silicate of soda solution, Weavingthe cords so treated into a basket Weave fabric having the Warp threadsand the Woof threads spaced at equal distances apart .to give equallongitudinal and transverse strength to the fabric, heating and dryingthe fabric, applying to one side only of the fabric so formed a coatingof plastic rubber and friction material, then subjecting the strip soformed 4to heat and pressure to force the plastic material i through theinterstices in the fabric, superposing a plurality of strips soformepd,With the coated side of each strip next the uncoated side of theadjacent strip, and subjecting the band so formed to pressure and heatto cure the rubber and form a homogeneous mass.

2. The method of manufacturing brake bands Which consists of twisting upyarns of asbestos fiber, forming these yarns into cords including fineWire strands,'ftreatmg these cords With a silicate of soda solution,Weaving n the cords so treated into a basket weave fabric i having theWarp threads and the Woof threads spaced at equal distances apart togive equal longitudinal and transverse strength to the fabric, heatingand drying theyfabric, applying. to one side only of the fabric soformeda.

coating of plastic rubber and frictionVmateheat and pressure toforce theplastic material through the 'interstices in the fabric, superposing aplurality of strips so formed, with the coated side of eachstrip nextthe uncoated side ofthe adjacent strip, subjecting the band so formed topressure and heat to cure the rubber and form a homogeneous mass, vandfinally treating the -product witha fire and Water proofing material andbaking the same.

3. The method of manufacturing brake bands Whichiconsists of twisting upyarns of asbestos fiber, for-ming these yarns into cords including lineWire strands, treating these cords with a permeating fire-proof liquidsolntion, Weaving the cords so treated into a woven fabric, heating anddrying the fabric, l applying vto one side only of the fabric so formeda coating ofl plastic rubber and fric- `tion material, thenl subjectingthe strip lso formed to heat and pressure to force the plas- .ticmaterial through ythe interstices in the ,n

fabric, superposing a plurality of vstrips so formed', With the coatedside of .each strip next the uneoated side of the adjacent strip,

les rial, then subjecting the strip so formed tof/ and subjectin theband so formed to pressure and heat o cure the rubber and form ahomogeneous mass. l j

4. The method -of manufacturing brake bands which consists of twistingup yarns of" asbestos fiber, forming these yarns into cords includingfine wire strands', treating these cordswith a permeating fire-proofliquid, Weaving the cords `so treated into a Woven fabric, heating anddrying the fabric, applying to-one side only of the fabric so formed acoating of plastic rubber and friction 1na.

terial, then subjecting the strip so formed to heat and pressure toforce the plastic material through the interstices in the fabric, su-

.perposing a plurality of strips so formed,

with the coated side of each strip next the uncoatedside of the adjacentstrip, subjecting the band so formed to pressure andL heat to Acure 'therubber and form a homogeneous mass, and finally treating the productwith a cords 'with a silicate of soda solution, weaving,

fire and Water proofing material 'andjbaking the same. I

e 5. The method of manufacturing brake bands which consists of twistingup yarns of` asbestos fiber, forming these yarns into cords includingfine Wire strands, treating these the cords so treated into a wovenfabric, heating and drying the fabric, applying to. one

side only of the fabric so formed a coating v of lplastic rubber andfriction material, then subjectingthe strip so formedto heat andpressureto force theplastic material through fthe interstices in the fabric,superposing a plurality of strips so formed, with the coated side ofeach strip next the uncoated side of the adjacent strip, andsubjecting'the band soformed to pressure and heat t0 cure the rubber andform a homogeneous mass.

6. The method of manufacturing brake bands which consists of twisting upyarns of asbestos fiber, forming these yarns into cords including fineWire strands, treating lthese cords With a silicate ofhsoda solution,Weaving the cords'so treated into a Woven fabric, heating and drying thefabric, applyingto one side only of the fabric so formed a coating of ofplastic rubber and friction material, then ber and form a homogeneousmass, and finally A treating the product with .a fire and water proofingmaterial and bakin the same.

RICHAR J. EVANS; Y

